Pamela R. Roberts - Comprehensive Critical Care: Adult

Part 1: Neurological Critical Care

Stuart McGrane, MBChB, MSCI, Pratik P. Pandharipande, MD, MSCI, and Christopher G. Hughes, MD

Fred Rincon, MD, MSc, MBE, FACP, FCCP, FCCM

Scott A. Marshall, MD, and Geoffrey S. F. Ling, MD, PhD, FAAN

Sherry H-Y. Chou, MD, MMSc, FNCS

Part 2: Cardiovascular Critical Care

Antoinette Spevetz, MD, FCCM, FACP, and Joseph E. Parrillo, MD, FACC, MCCM

Michael R. Pinsky, MD, CM, Dr h.c., FCCP, MCCM

Felix Y. Lui, MD, and Kimberly A. Davis, MD, MBA

Chapter 8: Severe Heart Failure, Cardiogenic Shock, and Pericardial Tamponade
(Including Principles of Intra-aortic Balloon Pumps and Ventricular Assist Devices)

Etienne Gayat, MD, PhD, and Alexandre Mebazaa, MD, PhD

Sachin Yende, MD, MS, David T. Huang, MD, MPH, and R. Phillip Dellinger, MD, MCCM

Deepa M. Patel, MD, and Craig M. Coopersmith, MD

Fredric Ginsberg, MD, FACC, FCCP, and Joseph E. Parrillo, MD, FACC, MCCM

Ravi Agarwala, MD, FRCPC, Sean Patrick Whalen, MD, and Natalie Bradford, MD

Chapter 13: Valvular Heart Disease, Acute Aortic Dissection, and Patient Care
After Cardiac Surgery

Michael H. Wall, MD, FCCM, and Pamela R. Roberts, MD, FCCM

Amanda M. Gomes, MD

Marcos Emanuel Gomes, MD, and Pamela R. Roberts, MD, FCCM, FCCP

Stylianos Voulgarelis, MD, and Sylvia Y. Dolinski, MD, FCCP

Part 3: Respiratory Critical Care

Nicholas C. Watson, MD, and Stephen O. Heard, MD

Eric Ursprung, MD, and Theofilos P. Matheos, MD

Debasree Banerjee, MD, MS, Jeffrey Mazer, MD, and Nicholas Ward, MD

Jennifer A. LaRosa, MD, FCCM, FCCP, and R. Phillip Dellinger, MD, MCCM

Neil R. MacIntyre, MD

Kenneth E. Wood, DO, and Jason A. Stamm, MD

Scott E. Kopec, MD, FCCP, and Marie T. Mullen, MD

Robert A. Balk, MD

Part 4: Critical Care Infectious Diseases

Ryo Yamamoto, MD, and Ramon F. Cestero, MD, FACS

Gourang Patel, PharmD, MSc, and Anand Kumar, MD

Gloria Vazquez-Grande, MD, and Anand Kumar, MD

Shravan Kethireddy, MD, Anna Chen, MD, Jonathan Perez, MD, and Mary Jane Reed, MD, FCCM

Part 5: Hepatic, Gastrointestinal, Hematologic/Oncologic Disease in the ICU

Vinod P. Balachandran, MD, and Soumitra R. Eachempati, MD, FACS, FCCM

Adil M. Abuzeid, MBBS, and Nabil M. Issa, MD

Mario Raul Villalba, MD, FACS, and Martin A. Schreiber, MD, FACS

John Crommett, MD, and Joseph L. Nates, MD, MBA, FCCM

Part 6: Renal and Metabolic Disorders in the ICU

Chapter 33: Acute and Chronic Renal Failure and Management (Including Hemodialysis and
Continuous Renal Replacement Therapies)

Michael L. Bentley, PharmD, FCCM, FCCP, FNAP, and Ashita J. Tolwani, MD, MSc

Alisha Bhatia, MD, and David M. Rothenberg, MD, FCCM

Linda L. Maerz, MD, FACS, FCCM

Gozde Demiralp, MD, and Pamela R. Roberts, MD, FCCM, FCCP

Nestor Arita, MD, Jeremy L. Ward, MD, and Paul E. Marik, MD, FCCM, FCCP

Pamela R. Roberts, MD, FCCM, FCCP

Part 7: Environmental and Toxicologic Injury

Todd Huzar, MD, and James M. Cross, MD, FACS

Michael Sirimaturos, PharmD, BCNSP, BCCCP, FCCM, Rebeca L. Halfon, BS, PharmD, and
Janice L. Zimmerman, MD, MCCM, FCCP

Janice L. Zimmerman, MD, MCCM, FCCP

Part 8: Pharmacologic Issues in the ICU

Quinn A. Czosnowski, PharmD, and Craig B. Whitman, PharmD, BCPS, BCCCP

Brian L. Erstad, PharmD, MCCM, and Courtney McKinney, PharmD

Part 9: Surgical and Obstetrical Critical Care

Yatin Mehta, MD, Jaya Sugunaraj, MD, Mark A. Kleman, DO, M. Camilla Bermudez, MD, Heather J. Johnson, PharmD, Patricio Andres Sanchez-Cueva, MD, and Mary Jane Reed, MD, FCCM

Sherry Sixta, MD, and Rosemary Kozar, MD, PhD

Christina C. Kao, MD, Tashinga Musonza, MD, Lillian S. Kao, MD, MS, and S. Rob Todd, MD

Jennifer E. Hofer, MD, Karen C. Patterson, MD, and Michael F. OConnor, MD, FCCM

Part 10: Administrative and Ethical Issues in the Critically Ill

Sara R. Gregg, MHA, and Timothy G. Buchman, MD, PhD, MCCM

Jean-Louis Vincent, MD, PhD, FCCM

Andrew M. Naidech, MD, MSPH

Fred Rincon, MD, MSc, MBE, FACP, FCCP, FCCM

Altered Mental Status During Critical Illness: Delirium and Coma

Stuart McGrane, MBChB, MSCI, Pratik P. Pandharipande, MD, MSCI, and Christopher G. Hughes, MD

Key words: delirium, coma, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), Intensive Care Delirium Screening Checklist (ICDSC), Richmond Agitation-Sedation Scale (RASS)

Critically ill patients often manifest varying degrees of altered mental status secondary to their acute disease processes or as a consequence of the therapies used to treat disease. These mental status changes range from coma to hyperactive delirium. A comatose patient is unresponsive to physical or verbal stimuli, whereas delirium is an acute and fluctuating disorder of consciousness characterized by inattention, disorganized thinking, and perceptual disturbances ( Figure 1 ). Alterations in mental status have traditionally been considered expected consequences of critical illness, and clinicians are increasingly aware that these mental status changes are manifestations of acute brain organ dysfunction that are associated with worse clinical outcomes. Early studies evaluating coma and delirium were hampered by the many different terms (eg, confusional state, ICU psychosis, acute brain dysfunction , and encephalopathy ) used to describe altered mental status during critical illness. Additionally, the lack of validated bedside tools (besides the comprehensive Diagnostic and Statistical Manual of Mental Disorders ) to diagnose delirium prevented the incorporation of delirium monitoring into routine clinical care in the ICU.

Figure 1. Delineation between delirium and coma, highlighting the cardinal symptoms of delirium

aOptional symptoms of delirium (may be present but are not required for the diagnosis of delirium).

DIAGNOSIS OF ACUTE BRAIN DYSFUNCTION

Traditionally, many scales have been available to assess the level of sedation and agitation in ICU patients, including the Ramsay scale, Riker Sedation-Agitation Scale (SAS), motor activity assessment scale, and Richmond Agitation-Sedation Scale (RASS). The recent guidelines on pain, agitation, and delirium from the Society of Critical Care Medicine recommend the use of the RASS and SAS due to their psychometric properties and validity in critically ill patients. The RASS ( Figure 2 ) also has been shown to detect variations in the patients level of consciousness over time or in response to changes in sedative and analgesic drug use. As a first step in assessing the level of consciousness, a sedation-agitation scale should be used. Patients who are unresponsive to verbal commands (eg, a RASS -4 or-5) are considered to be in a coma and cannot be evaluated for delirium at that time. Patients who are responsive to verbal stimuli (eg, RASS -3 and lighter) can further be evaluated for the content of that arousal via the use of delirium monitoring instruments.

Figure 2. The Richmond Agitation-Sedation Scale (RASS)